Tuberculosis (TB) is a major infectious disease with significant morbidity and mortality worldwide. The only currently licensed vaccine against TB is the Bacillus Calmette-Guerin (BCG) vaccine. Unfortunately, this vaccine confers poor protection against adult pulmonary TB and has been associated with adverse events. Therefore, the development of a novel, effective vaccine that induces long-term protection against TB is urgently needed. However, due to a variety of factors only a few antigens which have been determined to induce T cell immunity against TB have been studied so far. These include Ag85A, Ag85B, ESAT6, TB10.4, and Mtb39a. One issue is that there are many TB antigens from which to choose and current technologies for delivering TB antigens are limited and expensive.
There remains a need for economical and effective TB vaccines and methods that can induce immune responses against immunogenic TB antigens, protect against TB infection and provide effective treatment to individual who are infected with TB. There is also a need for a cost-effective delivery system to enable mass prophylactic vaccination against TB.